Art of treating fibrous material.



ran snares PATENT orrron BENJAMIN C, MUDGE, OE BOSTON, MASSAOHUSETTS, ASSIGNOR TO- WILBUR M. STONE, TRUSTEE, OF NEW YORK, N. Y. A

ART OF TREATING FIBROUS MATERIAL.

To (LZZ whom it may concern):

Be it known that I, BENJAMIN C. MUDGE, a

' citizen of the United States, residing in Bos- :lowing is a specification.

My'invention relates to the manufacture of flax, linen, or other fibers, and especially to the production of linen fiber of superior quality for use in the mechanical arts. 1

' More especially, my invention pertains to the transformation or removal, or both, from flax fiber of those portions of the flax plant or stalk known in the art as shiyes, boon, or sprite, and is in part in the nature of an'improvement upon the subjectmatter disclosed and. claimed in United States PatentNo. 732,103, granted to me June 30, 1903.

My improved process is aiso' applicable both to manufactured or partially manufactured flax or linen products.

I have found that the fiber constituting the shive part of the flaxstraw is substantially of the same nature as the fiber constitutingthe long line fiber or linen of the plant and that when reduced to its ultimate or net fibrous condition theseshive fibers may become a part of the flax or linen fiber of commerce and be useful in likemanner.

My present improvement is applicable, as is my before-mentioned invention, to the treatment of flax generally, including the flax waste or ordinary flax tow of commerce. Usually and preferably the flax is first subject-ed to a preliminary or partial deshiving, which may be accomplished by well-known mechanical. means with efficiency and economy. In this preliminary deshiving I preferably use some well-known meanssuch, for instance, as an ordinary duster mechanismand a modifiedwoolen-garnet machine. The fiber is thus cleaned of refuse and loose foreign matter and a quantity of the shives are mechanically removed from the fiber. The state of the fiber after being thus treated is partially deshived and is in a general way commercially called deshived'f Under the general term shive I include all such parts of the flax-plantlas are of a'woody or strawlike nature, this referring especially to the plant stalks and stalk The flax is Specification ofLetters Patent. Application filed Novemher 18,1903. Serial No. 181,633.

Patented Sept. 25, 1 906.

. next subjected to the operation-of degumming. This consists in a partial dissoclation and partial removal of the gum, lignin,

pectose, fatty acids, and wax-like substances." For this treatment the bath is alkaline and may be composed of any suitable alkali, but I preferably employ the same ingredients, to wit, soda-ash and caustic soda, as used in my already patented improvement; but I these materials have a better and also a more eflicient action than those stated in my be have found that substantially equal parts of fore-mentioned patent. This bath I preferably use at about 3" Twaddell and at a temperature of.about the boiling-point or up; ward. This temperature (if above boiling) I obtain, preferably, by steam heat in a digester, and I preferably use a digester'which' can be agitated or rotated, as I find that the agitation of the material operated upon with respect to its container, or vice versa, tends to hasten and render more effective this operation. This also applies, generally speaking, to the other chemical operations and rinsingsinvolved inpracticing my improved process. The said agitation tends to hasten these various operations by affording the liquors of said baths respectively a larger opportunity for contact with the material subjected to their acti n. by washing away from contact with the fiber such portions of the liquor as are more or less spent, and to thereby tend to facilitate the supply of liq: nor of maximum strength 'to the various parts of the material treated and also to mechanically remove portions of the matter acted upon. In the foregoing bathsubstantially equal proportions of soda-ash and caustic soda are used, for the reason that I believe said chemicals when so used roduce a materially lessharsh action on tie fiber and are under better control. -feasible and I have with a large measure of It is also success used in this bath either of these ingredients to the exclusion of the other by sufficiently increasing the quantity of the one to compensate for .the absence of the other or to compensate for variations in time or temperature; but, as above stated, I deem.

substantially equal pro ortions especiallyadvantageous as regar s chemical action and also as to economy in cost as compared with the work accomplished. After the flax has remained a suflicicnt time in this bath I draw ofi the liquor or remove the fiax' therefrom and thenpreferably rinse with water.

The next sta e of the treatment is souring. For this I Sub ect'the flax to the action of slightly-acidulated water, preferably by'immersing the flax therein, and I have found that three-quarters of an hour is usually a sufficient time in which to accomplish the desired result. I then submit'the flax to hypochloritic action, which results in indirect oxidation of the extraneous organic and inorganic non-fibrous matter by the union of its hydrogen with the chlorin, thereby liberatingl' he oxygen of said extraneous matter, Whic' thereupon. performs its well-known bleaching "action. Coincident and coeper'ative with this action is the continued disintegration of the shive masses through the union of the chlorin with their ligmn and otherfcementitious matter, thereby forming a solubieehim'd of lignin and other chlorids which are disseminated through the bath. This hypochloritic bath may be prepared with various ingredients and by various methods; but I have found the following ingredients and method to be economical and eficient. Id-issolve six and one-half parts of chlorid of lime, one part of soda-ash, one part of'caus'tic soda, and one and one-tenth parts of sulfate of magnesia in a suflicient quantity of water, preferably at about 90 Fahrenheit, to show about Twaddell.

' The specified-proportions of these ingredicuts are approximate. I preferably use only the clear liquor resulting from this mixture and remaining after the settli'n out and slimming off of impurities and re erably at a temperature of about 120 Fa renheit.

After the. hypochloritic treatment abo've set forth I treat in acidulated water for a suitable .-periodfor instance, about onehalfhour wit'h the objectsin view, among others, of furtherjdissolving such compounds as may have been formed by the prior treatment, thefurther direct action upon the gums and cements constituent in the mass more readily susceptible to the action of acids, and toput the material into better 'co'nditio'n'to properly receive the subsequent chemical treatment. For this acid treatment I usually and preferably employ as a suitable acid about oneeighth per cent. of

sulfuric acid. The acid employed and itsstrength, asfwell as its temperature and theduratlon ofits action, must vary and depend.

upon each other to some extent and upon the natural features of the plant or flax being treated. In this connection I have found that other acids-such as chlorhydric, ni

tric, acetic,ox'alic, and others ive good'results, and some of these being milder in their action are sometimes preferable where itis desired to treat the fiber with great care and conserve all its natural features for the production of a fine fiber. For these reasons such acids may be used as alternatives and of a strength in proportion. It is to be noted in this connection that geographical location,

soil, and climatic conditions have substantial effects upon the growth and quality, coarseness or otherwise, of the plant fiber and the proportions of cementitious constituents or matrix to the volume of the fiber of the plant. Also there is a marked difference in the readiness with which the shive por tions of these various plants may be broken and removed by mechanical means, and consequently in the relative quantity of shives remaining to be treated by chemical action.-

Before treating in aoidulated water, as last stated, I may rinse, by agitating in water or otherwise, the mass under treatment, and

under some circumstances this is "deemed -desirable. I have found, however, that generally and in what I deem the best practice the carrying over of a part of the hypochlorites associated with the fiber into the acid-bath is,

beneficial, and I therefore generally prefer. to omit this Washing. Among these benefits are a better control of the operationsrof the process through the balancing of the action of one chemical against another, and by reason of the already close association ofthe hypochlorites with the flax fiber the acid-bath evolves a chlorin gas in immediate contact with the flax fiber, showing the bleachingthereof and the relative condition and progress of the operations of the process. After this acid treatment I rinse the flax in water. This and the degree'of the rinsing 'w ill dependu on the exact nature of the chemicals emplhyed and of the antichlor to follow. Resulting from previous chemical action undesirable by-products and insoluble salts have resulted, such as sulfate of lime and sulfate of calcium, which exist as deposits on the. fiber. If not removed, these deter pro ress and obstruct the action of the antichlor. Also in the subsequent use of certain antichlors some acid would coiiperate and be beneficial, and in such case it need not be removed by rinsing. Respectin this rinsing, therefore, and the selection of t e subsequent antichlor, judgment should be used. Either the acid must be washed out or an antichlor employed to which acid is no objection, or the non-soluble deposits must be removed before employing an antichlor to which they are obstructive.

Following the acid treatment I then stop the further action of any re'maining-chlo'rin by submitting the mass und r treatment to the action of an antichlor, kreferably acid sulfite of calcium in'an aquaus solution. I give preference to acid sulfite of calciumyas I have discovered that it possesses superior antichlor properties and on account of the bleaching. properties 'of said'acid suflfite and also because-it unites with and dissolves the lignin, thereby'continuing'the disintegration "Ward the disintegration of the shives and the bleaching thereof. I find in practice that-in combination with either of the above-mew tioned antichlors the addition of an acid tends to augment and accelerate the operation of the antichlor and the results mentioned. It is known that hyposuliite of soda is an antichlor and it maybe used instead of either of the foregoing compounds in this bath. but ithas little or no effect in assisting the disintegration of the shives or in bleaching. This material is, however, of low cost,

and therefore may be used with economy locally, because of its efficiency as an antichlor only. An objection to the use of hyposuliit-e of soda is thata'depos'ition of flowers of sulfur adhering to the fiber in an amorphous sticky condition may "result from its contact with certain acids,-such as sulfuric 5 acid, impairing the process and diminishing the qua ity and value of the product. I have also. discovered that acid 'sulfid of calcium, bisulfite of soda, and hyposulfite of soda may be used together, mixed in varying proportions as an ,antichlor, disintegrator, and 'bleacher of shives. An advantage of this mixture is an economic one, hyposuliite of soda being possibly the cheapest and most common, and its efficiency can be increased more than proportionate to the additional cost by the addition of either one or both of the other two.

After the antichlor treatment we now have a mass of fiber remain ng partially incased in its organic gumsand vegetable-matrix combined with a remnant of coloring-matter, and all of which substances so associated with the fiber have been influenced and modified by previous treatment, whereby they are made susceptible to further treatment by different or other and gentler means. A substan-' tially further continuance of the means heretofore used has been found injurious to the fiber now less rotected by its organic gums than previous y, whereas said' gums have now been rendered susceptible to treatment by means not previously effective. -The mass composed as last treated by me will have entrained therein a remnant of the antichlor with the by-products resulting from itsaction, and it is therefore important to remove mechanically by washing, rinsing, or draining these now foreign substances. The carrying over of these substances Wlll both impede and tend to counteract the action of the subsequent chemical treatment. I then This agent I do.

submit this fibrous mass consisting of partiallyrbleached iiax fiber and partially-disintegrated and partially-bleached shives to a further and direct oxidation. The object of .this treatment is to complete the disintegra- .,t, ion of the shive portion of the mass and, inciden tally, to remove any remaining coloringmatter, whether organic or stains, from foreign sources. The oil'ice of this solution is to provide oxygen in a form to readily combine upon contact with the gums and other nonfi )rous components;

it has been stated that the fibrous portions have been partly freed from their organic gums and other-incasing substances and that they are now, therefore, more exposed to injury by harsh treatment, whereas the gums and other associated substances require further treatment for their complete removal. The chief characteristic of the process heretofore has been the alternate treatment by alkaline and acid solutions. It is now necessary to keep the dividing-line between these two conditions a narrow one and under-ready and quick control. The oxidizing solution should be kept always on the acid side. If not, it will result'in thc speedy destruction of the fiber, for the reason that in a non-acid, neutral, or alkaline solution the oxidizing agents will at once attacktbe cellulosic tissues'and convert them into oxycellulose, This destructive action'carried even to a small extent would materially injure the fiber by weakening it, and thus reduce its value. The base of this oxidizing solution is an acidulated water, in which the oxidizing ingredients are dissolved in desired proportions. As oxidizing ingredients 1 preferably employ permanganate of otash, in combination with chlorate of potas in proportions to suit the purpose. The advantage of employing both is that the'chlorate assists and makes Ingre -active the oxidizing effect of the permanganate of potash, and is therefore a factor in the control and in the intensity ofthe action. The dominant factor as an oxidizing agent is the permanganate of potash. This may be.

used alone or in' combination with other things, and I have found it to be highly ac-.

nate of potash I have foundvaluable results from the use of sulfate of magnesia instead of the chlorate of potash; but if used its proportion tothat of the permanganate should preferably be substantially equal. v There are doubtless other alternative assistants.

There are also other oxidizing agents which bath of manganate of soda may be substie tuted for permangana of potash, but with less beneficial results.

. dissolve these ingredients in. an acidulated water. This acidulation is very slight, but should be acid in fact and enough to counteract the influence of any alkali and to prevent the oxygen attacking the fiber. 'The exact or extreme degree of the acidulation may therefore vary and if excessive may be corrected by the addition of further alkali. The strength of the bath in oxidizing ingredients is preferably less than 1 Twaddell. Inci dental to the application of this bath the fibrous mass-assumes a reddish-brown color, indicating the proper action of the bath and its progressive degree in the formation of peroxid of manganese. Upon attaining this color, which isusually assumed in substantially less than-one hours time, depending upon the mechanical means employed toapply the liquor and the strength of the ingredients and the temperature, it is ready-for another rinsing.

The previous operations haveresolved the bulk of the lignin into chlorid of lignin and the fpectose intometapectic acid, the bulk of which have by this time been dissolved in the various baths. The effect of this oxidizing treatment upon the'fibrous mass is to complete the dissociation of the shive fibers and to convert the remaining lignin and pectose into soluble compounds and to render finally soluble the remaining gums, the removal of which carry with them any-remaining coloring-matter. -These conditions are indicated bythe degreeof the brown color above referredto. I thereupon rinse the fibrous mass with water to assistin removing entrained portionsof the solution and to-remove such ortions of said mass remaining as are solublein water or removable thereby. I -then subject the fibrous mass to a bath, commonly 'known as a discharging-bath]?which discharges or removes-the color imparted by the permanganate bath andany remaining organic coloring-matter and disintegrates any last vestiges of shives and does this while preferably use a solution of acid sulfite of calj avoiding any injury to the fiber, This bath comprises an-acid solution of sulfur, andI cium in slightly-acidulated water. From this solution" is liberated sulfurous-acid. gas.

I also preferably use this at a high tempera tare, approximately boiling, thereby facili- .ta ting the liberation of the sulfurous-acid gas.

I have-had good results in using acid sulfite (if-calcium and sulfuricacidin about the promrtion --of f ur ofithe-former to one of the la The-strength of 'thisbath .in acid s ilfiteof calcium and in the acid used to acidu-iate the water will be influenced by ithe-teim preserve the fiber.

peratureand should be sufficient to comcolor may reappear.

It has already been mentioned in the case of the flaxeplant that a substantial variation is found'in the quality and size of the fiber and its tenacity or resistance to treatment both when considered chemically as to its constituents and mechanically as to their hardness and tenacity. For these reasons these various stages of the process and the several chemical treatments affect the shive portions and cementitious gums differently. It may not be feasible to say at just what stages in the operation the disintegration of the shives and cements takes place, and it is perhaps immaterial to know or to state this definitely. It is known, however, that each successive action tends to weaken the stability of the shive as a unit, and its'size and the relative amount'of work to be done in its disintegration will somewhat depend upon its size and the mechanical agitation applied to it. As its cementitious bond becomes pro essively weaker mechanical a itation wil tend further to reduce it. v hat is of greater importance is the fact that it becomes constantly more susceptible to treatment, and the objectof the process and the skill involved in its practice is to apply to the constantly-weakening shive an influence suflicient to disintegrate it and not affect detrimentally the fiber which is being more and more denuded of the coatings which originally protected it. It is also known that each step in the process renders the fibrous mass more susceptible to the influence of the succeeding step. Therefore the intensity of the treatment is progressively decreased to It is further known that temperature may be used as 'a powerful factor. Temperature do's'two things. It makes more active the properties of. the chemicals per se and also makes more susceptible to their action or influence the subject-matter under treatment Withoutafiectingin the same way the fiber.v In the pract1ce of the art, therefore, these conditlons should be regulated'accordingly; Itais also pertinent to note that the, factor, of or duration is of importance and wields a powerful influence. at all stages ofthe process and conditions'fofcthe' mass under treatment, depending uonthe particulars of those. features, as the aotual'state of the fiber itself is at no time affectedor impaired-it is increasingly denuded of protecting covsrsg but the ingredients sought-tote removed, as well as,

the previously-combined elements and the byproducts, require time for their interchangeable action on each other, and the relative proportions and strength employed make it necessary to vary their exposure to the influence of each other. In some cases a chemical strength su'llicient to quickly influence the extraneous portions of the mass would be injurious to the fiber, and more time must therefore be permitted for this action in lieu of an increase of stremrth.

I. claim 1. That improvement in the art of treating fibrous plants which consists in subjecting the same properly prepared to the action of an alkali, then to an acid treatment, then to the action of hypochlorite of magnesia, then to an acid treatment, then to the action of an antichlor, then to a peroxidtreatment, and

then to the actionof sulfurous-acid gas, each in successively-decrezising chemical intensity.

2. That improvement inthe art of treating llax and analogous fibrous materials which consists in subjecting the same to an aqueous alkaline solution at a temperature above boiling, then to a hypochlorite, then to an antichlor, and thcn to oxidation and discharge.

3. That improvement in the art of treating llax and analogous fibrous materials which consists in partially degumming and partially deshiving fiber, then subjecting the same to the combined. action of the hypochlorites of soda and magnesia, then to an acid treatment, then to the action of acid sulfite of calcium, then to the action of permanganate ol potash, and then to the action of SUllUIOUS-M'hi gas.

4. That improvement in the art of treating flax and analogous fibrous materials which consists in partially degumming and partially deshiving fiber, then subjecting the same to the action of a chlorid, then to the action of an antichlor, then to the action of an oxidizing agent, and then to the action of a discharging agent.

. 5. That improvement in the art or treating flax and analogous fibrous materials which consists in subjecting the flax, previously suitably prepared, to the following series of treatments in successively-decreasin chemical intensity, the same being applied hot and in the order named: an alkaline treatment; an acid treatment; a hypochloritie treatment, an acid treatment, an antichlor treatment; a water treatment; a peroxid treatment; a sulfurous-acid-gas treatment, and a water treatment.

6; In the decomposing and removal of the organic gums and stalk units of,flax,'the art \whieh consists in the application of a series of successive and alternate alkaline and acid solutions to the plant 1nass,'followe(l by an antichlor to check further action of said solutions, and followed by an oxidizing solution and a discharging solution.

7. In the decomposing and removal. of the organic gums and stalk units of flax, the art which consists in the application of a series of successive and alternate alkaline and acid solutions of the plant mass, followed by an antichlor to check further actions of said solutions, and followed by a solution of peifoxjd of manganese and agents to generate a Suf furous-acid gas adjacent to the plant fiber.

Signed at Nos. Qto Murray street, New York, N. Y., this 12th day of November,

BENJAMIN c. MUDGE. 

